1. Technical Field
This invention relates to medical devices for mixing and extruding medically useful compositions, such as those used as bone replacement materials.
2. Background of the Invention
Certain medically useful substances are composed of component parts that require mixing prior to use. One such example is the mixing of the components used in preparing compositions as replacement materials for bones. Bone replacement materials typically are composed of a mineral component and a glue that surrounds and binds the mineral component. Often the mineral component is a calcium based mineral, and the glue component is a fibrin glue. The fibrin glue is formed by mixing fibrinogen and thrombin components.
Bone replacement material is typically mixed using a mortar and pestle and then applied as a paste. The mortar and pestle method, however, often destroys or greatly compromises the integrity of the fibrin glue matrix. This is due to the mechanical grinding action associated with using the mortar and pestle. Other similar methods involve mixing of the components on a flat surface using a spatula or like implements. In this regard, another disadvantage of current methods of mixing bone replacement materials is that they do not provide for final mixtures wherein the component parts are distributed homogeneously and in precise quantities.
There is therefore a need for medical devices that facilitate the mixing of substances that, when mixed, yield medically useful compositions. More specifically, there is a need for such devices that can conveniently and efficiently mix the component parts of bone replacement materials. Ideally the devices should be of a nature such that the mixing of the component parts, as well as the ultimate extrusion of the final composition, can be carried out wholly within the devices themselves.